Technical Field
The present invention relates to a device and a method for interrupting battery current. More particularly, the present invention relates to a device and a method for interrupting battery current using a latch relay for substantially high current interruption, enabling the latch relay to return to an ON position after operating to an OFF position.
Background Art
When a short circuit occurs at a ground side of a vehicle power line due to a collision or another abnormal condition, a fire may occur due to an overcurrent condition. To prevent such an overcurrent condition, a battery current interrupting device using an inflator (e.g., gunpowder explosion) or a latch relay may be used. In a case of the battery current interrupting device using the inflator, when a vehicle collision is sensed, current is applied in an airbag engine control unit (ECU) so that the current interrupting device performs an OFF (open) operation, thereby interrupting battery current. However, this system is inconvenient because performing an ON (closed) operation after an OFF operation should be performed by repairing or replacing the current interrupting device in a service center.
As a result, when the battery current interrupting device uses an inflator, the current interrupting device is operated only as a result of a vehicle collision. Also functionally limiting, is that the current interrupting device my not be configured to interrupt battery current when overcurrent is generated by an abnormal state except as a result of a vehicle collision.
FIG. 1 is an exemplary circuit diagram illustrating a conventional high current interrupting device using a latch relay. FIG. illustrates a battery 10, and a substantially high current interrupting control device 20 including a latch relay. The substantially high current interrupting control device 20 using the latch relay senses a substantially high current/short circuit in a vehicle collision or another abnormal state, and allows the latch relay to open, interrupting the battery current at the moment when the substantially high current/short circuit is sensed. A user may operate the substantially high current interrupting control device 20 to enable the latch relay to return to a closed (ON) position allowing flow of the battery current when the user desires. The substantially high current interrupting control device 20 may be configured to open the latch relay when sensing a substantially high current/short circuit during a vehicle collision or other abnormal state, so that interruption of the battery current, i.e., to hinder or prevent a substantially high current from flowing in a vehicle load or the like, may be possible. Accordingly, reducing a likelihood of a fire caused by an overcurrent state may be possible. However when the latch relay attempts to return to the ON (closed) position after operating to the OFF (open) position due to a vehicle collision or other abnormal state, the short circuit may coexist with the high current. In this case, there is a problem in that a contact point of the latch relay may be fixed and damaged by a substantially high current exceeding a standard current of the latch relay. In addition, the reuse of the latch relay may be impossible due to damage to the contact point of the latch relay, and therefore, the damaged latch relay should be replaced.